public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    private void Form1_Load(object sender, EventArgs e)
    {
        
        SaveAsBitmap(this,"C:\\f1.bmp");

        //The same way you can pass the controls like button,dataGrid etc
        //SaveAsBitmap(mydataGrid,"C:\\report.bmp")
    }

    public void SaveAsBitmap(Control control, string fileName)
    {   
        //getthe instance of the graphics from the control
        Graphics g = control.CreateGraphics();
        
        //new bitmap object to save the image
        Bitmap bmp = new Bitmap(control.Width, control.Height);

        //Drawing control to the bitmap
        control.DrawToBitmap(bmp, new Rectangle(0, 0, control.Width, control.Height));
        
        bmp.Save(fileName);
        bmp.Dispose();
        
    }
    
}